Presentation Abstract

Recent work on marine survival in Chinook and coho salmon and steelhead trout has shown a decline in marine survival in the Salish Sea that was not evident in other regions. For Chinook, the decline was not explained well by oceanographic patterns, and for coho, regional-scale patterns were suggested as important in understanding survival. Recent work on the development of indicators of Puget Sound steelhead survival has shown that predator abundance and patterns in hatchery releases, as well as oceanographic conditions are informative in predicting marine survival. While the three species of focus for the Salish Sea Marine Survival Project have different life-histories, and are therefore subjected to variable pressures at multiple scales, this current analysis aims to answer three questions: 1.) Are there similarities in survival trends among the three species? 2.) Do regional patterns in survival emerge when survival trends are evaluated concurrently across the three species? 3.) Does release strategy (yearling or subyearling) confer a survival advantage, and if so, is this consistent across all species? To evaluate survival time series, we used multivariate time series analysis with multiple groupings (species, spatial, and release strategy) to identify commonalities among species. Observed commonalities will aid in the development of indicators of marine survival for coho and Chinook by focusing efforts on appropriate spatial or temporal attributes. A hypothesis-driven approach similar to that employed for the development of indicators for steelhead survival will be used to relate coho and Chinook to environmental, biological, and anthropogenic factors influencing survival.

Session Title

The Salish Sea Marine Survival Project: Understanding Salmon Survival

Keywords

Ecosystem indicatiors, Time series

Conference Track

SSE11: Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE11-418

Start Date

5-4-2018 1:45 PM

End Date

5-4-2018 2:00 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 5th, 1:45 PM Apr 5th, 2:00 PM

Comparing marine survival among Chinook and coho salmon and steelhead trout in the Salish Sea

Recent work on marine survival in Chinook and coho salmon and steelhead trout has shown a decline in marine survival in the Salish Sea that was not evident in other regions. For Chinook, the decline was not explained well by oceanographic patterns, and for coho, regional-scale patterns were suggested as important in understanding survival. Recent work on the development of indicators of Puget Sound steelhead survival has shown that predator abundance and patterns in hatchery releases, as well as oceanographic conditions are informative in predicting marine survival. While the three species of focus for the Salish Sea Marine Survival Project have different life-histories, and are therefore subjected to variable pressures at multiple scales, this current analysis aims to answer three questions: 1.) Are there similarities in survival trends among the three species? 2.) Do regional patterns in survival emerge when survival trends are evaluated concurrently across the three species? 3.) Does release strategy (yearling or subyearling) confer a survival advantage, and if so, is this consistent across all species? To evaluate survival time series, we used multivariate time series analysis with multiple groupings (species, spatial, and release strategy) to identify commonalities among species. Observed commonalities will aid in the development of indicators of marine survival for coho and Chinook by focusing efforts on appropriate spatial or temporal attributes. A hypothesis-driven approach similar to that employed for the development of indicators for steelhead survival will be used to relate coho and Chinook to environmental, biological, and anthropogenic factors influencing survival.